In the field of non-volatile media (NVM), as storage elements are forced closer and closer together to achieve smaller products, the storage elements have reduced physical isolation. This reduction in physical isolation, as well as natural variations that arise from a complex manufacturing process, result in a variety of defects, such as storage elements with high read and/or write error rates. For media that use a thermal process to encode the state of the storage element, such as phase change media, thermal effects propagate to surrounding storage elements. This document refers to these propagated thermal effects as disturb coupling. Disturb coupling may result in a change in the state of the surrounding storage elements (victim elements). This may be mitigated at the cost of greater thermal isolation through choices of substrate, greater physical segregation, or by concurrent programming of the coupled elements. Each approach, however, has some limitations in the cost, complexity, and/or performance. As such, complementary to NVM design choices to eliminate or reduce disturb coupling, it is advantageous to actively manage coupling and its effects.
Defect remapping schemes may implement re-vectoring schemes, wherein a logical address associated with a defective physical region is directed to a different physical region. Exchanging one set of neighbors for another results in a different set of proximity disturb relationships for the new physical region. For example, a managed unit of a memory may comprise a number of write units, pages, or other portion of memory laid out in a certain physical address order for a die. Remapping a portion of a managed unit could add a set of new neighbors to the existing set of disturb neighbors, increasing the complexity of identifying neighbors and the cost of remediation for the now expanded set of neighbor units.